Hearing aids are one type of ear worn acoustic device, and the technology to implement hearing aids and other types of ear worn acoustic devices has progressed rapidly in recent years. Technological advancements in this field continue to improve the miniaturization, reception, wearing comfort, life-span, and power efficiency of these devices and well as permit an increasing number of styles and types of these devices. For example, there are several different hearing aid styles which include: Behind-The-Ear (BTE), In-The-Ear or All-In-The-Ear (ITE), In-The-Canal (ITC), and Completely-In-The-Canal (CIC). With the continual advances in the performance of ear-worn acoustic devices and demand for new types or styles of ear worn acoustic devices, ever-increasing demands are placed upon improving the inherent performance of the miniature acoustic transducers that are utilized.
Generally, a listening device, such as a hearing aid or the like, includes a microphone assembly, an amplifier and a receiver (speaker) assembly. The microphone assembly receives acoustic waves, and generates an electronic signal representative of these sound waves. The amplifier accepts the electronic signal, modifies the electronic signal, and communicates the modified electronic signal (e.g. processed signal) to the receiver assembly. The receiver assembly, in turn, converts the processed electronic signal into acoustic energy for transmission to a user.
Bone conduction speakers have been developed in various types to sense audible sounds through bone vibrations and to transmit the converted vibrations to the cochlea. The bone conduction speaker may include a yoke, a voice coil, a magnet, a diaphragm, a spring, and a vibration block housed within a case. The vibration block has its central portion mounted to the inner surface of the case through, for example, a plurality of screws. The spring has its outer peripheral portion fixedly embedded in an inner surface of the housing, and has its central portion fixedly mounted to a lower surface of a central portion of the yoke. This arrangement of the assembly has several disadvantages. Manufacture and assembly of the typical speaker may require complex, labor intensive particularly centering the vibration block to the case. Also, the physical volume of the material places limits on the size of the speaker making size reductions difficult.